This invention relates to methods for methane conversion to products such as chemical feedstocks, transportable solids and liquids, or other combustible fuels, and particularly to processes for converting methane to magnesium tricarbide, hydrolysis of magnesium tricarbide to C.sub.3 H.sub.4 hydrocarbon, and condensation/dehydrocyclization of C.sub.3 H.sub.4 to benzene, or the like.
Methane is the major constituent of natural gas and is a significant domestic fuel and chemical feedstock resource in the United States and other countries. There has been strong interest in developing new processes for converting methane to other useful products of potentially higher value for energy production, chemical manufacture, etc. Furthermore, a significant fraction of the world supply of methane occurs as so-called "remote" gas. "Remote" gas is natural gas found at locations "distant" (1000 to more than 12,000 miles) from major markets. Significant quantities (&gt;10 quads/yr) of remote gas are currently available dry or as a co-product of crude petroleum recovery. High transportation costs exclude remote gas from most major international fuel and chemical markets unless significant volumetric energy densification can be economically achieved. Simple compression to form compressed natural gas (CNG) is economically viable for shipping distances up to about 1000 miles. Longer transport distances demand more severe processing such as direct liquefaction (LNG production) or chemical conversion to other liquids such as methanol or Fischer-Tropsch (FT) hydrocarbons.
Methanol and FT liquids expand remote gas market options to utility and transportation fuels and to chemicals manufacture. However, established technologies generate methanol and FT hydrocarbons indirectly, by catalytically upgrading synthesis gas, expensively manufactured by reforming the remote gas. Thus there is now extensive research and development interest in new technologies for "direct" conversion of remote gas to economically transportable products.
Kim, et al., in Ind. Eng. Chem. Proesss Des. Dev., Vol. 18, No. 2 (1979), discussed the production of calcium carbide by passing a presized suspension of finely divided lime in methane or ethylene, or of finely divided lime and a bituminous coal in hydrogen, through a rotating-arc reactor.
However, there still exists a need for processes to economically upgrade methane into other useful products including products having economically transportable and usable forms.